Tides modulate crevasse opening prior to amajor calving event at Bowdoin Glacier, Northwest Greenland ...
Retreat of calving glaciers worldwide has contributed substantially to sea-level rise in recent decades. Mass loss by calving contributes significantly to the uncertainty of sea-level rise projections. At Bowdoin Glacier, Northwest Greenland, most calving occurs by a few large events resulting from...
Main Authors: | , , , , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
ETH Zurich
2020
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Subjects: | |
Online Access: | https://dx.doi.org/10.3929/ethz-b-000384152 http://hdl.handle.net/20.500.11850/384152 |
Summary: | Retreat of calving glaciers worldwide has contributed substantially to sea-level rise in recent decades. Mass loss by calving contributes significantly to the uncertainty of sea-level rise projections. At Bowdoin Glacier, Northwest Greenland, most calving occurs by a few large events resulting from kilometre-scale fractures forming parallel to the calving front. High-resolution terrestrial radar interferometry data of such an event reveal that crevasse opening is fastest at low tide and accelerates during the final 36 h before calving. Using the ice flow model Elmer/Ice, we identify the crevasse water level as a key driver of modelled opening rates. Sea water-level variations in the range of local tidal amplitude (1 m) can reproduce observed opening rate fluctuations, provided crevasse water level is at least 4 m above the low-tide sea level. The accelerated opening rates within the final 36 h before calving can be modelled by additional meltwater input into the crevasse, enhanced ice cliff undercutting by ... : Journal of Glaciology, 66 (255) ... |
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